I do some trivial modifications to my KDE desktop such as changing wallpaper and adding a few widgets. After I logout and then login again all my modifications are lost.
Additionally, the panel is missing and no windows is displayed for the started applications (only a rectangle of the window is shown when i pres Alt-Tab).
After some experiments I discovered that I can get bring back the panel and windows if I play with Activities, but it only lasts till the next logout.
I have no idea how to approach this issue, so any ideas are greatly appreciated.